1. Field of the Invention
The present invention relates to a method for applying text a picture or the like onto the surface, of plural plating layers or onto the surface of a vacuum plating layer formed an the plural plating layers using laser processing to form a mark (hereinafter, referred to as xe2x80x9claser markingxe2x80x9d), a method for applying another plating layer to a mark portion or coloring a mark portion with ink paint, or the like, and a product using these methods. The product refers to a faucet appliance which is attached to a water-supplied area of a toilet room, a washing room, a bathroom, a kitchen, and to other equipment including a faucet or fixtures for water supply or drainage, fixtures for sanitary ware, accessories, a handrail, and other peripheral apparatus.
2. Description of the Prior Art
Mark forming methods for displaying the name of a manufacturer, text, a picture or the like by forming a plating layer on the surface of a metal or resin product have been implemented in various fields. According to a general example on conventional arts, irregularities are formed on the surface of a base by hammering, carving, etching, laser marking or the like, and thereafter a plating layer is applied, so that the differences in brightness among the irregularities on the surface of the plating layer makes the mark distinguishable. There is another example in which a plating layer is applied, and thereafter hammering, etching, laser marking or the like is conducted.
Also, mark forming methods for coloring and displaying the name of a manufacturer, text, a picture or the like on the surface of a metal or resin product or on the surface of a plating layer formed thereon have been implemented in various fields. According to a general example among conventional arts, there is a method for forming a mark by directly printing to the surface of a base or the surface of a plating layer formed thereon, a method in which a concave portion is formed on the surface by cutting, carving, etching or the like, and a method in which a concave portion is formed on the surface and ink, paint, or the like is poured into the concave portion.
In addition, as a method using laser marking, there is a method in which a thin film is formed on the surface of a metal base by ion plating, the surface of the base is exposed by laser marking, and thereafter a gold plating layer is applied a method in which a masking layer is formed on the surface of a metal base, the surface of the base is exposed by laser marking, and thereafter ion plating is conducted. Such a method is disclosed in Japanese Unexamined Patent Application Publication No. 8-283962, or the like. Another method is known for forming a mark by attaching a printed seal or the like.
Drawbacks of the conventional method in which hammering, caving etching, laser marking or the like is conducted before plating, the mark is distinguished only by the brightness differences on the plating-conducted surface, the plating layer makes narrow and shallow lines vague and the mark is hard to see. Therefore, it is difficult to obtain a conspicuous mark.
Drawback of the conventional method in which hammering is conducted after plating also include the drawback that the mark is hard to see and also the plating layer in the hammered portion is subject to cracking and corrosion. Drawbacks of the conventional method in which etching is conducted after plating include the drawback that narrow lines cannot be drawn and also that the etched portion is subject to corrosion and discoloration. According to the conventional method in which laser marking is conducted after plating, narrow and clear lines can be drawn, however, corrosion will result if the processing depth reaches the base.
Drawbacks of the conventional method for forming a mark by directly printing to the surface of a base or the surface of a plating layer formed thereon, since there are cases where the adhesion is stall and the thickness of the printing is small depending on the kind of a base, include the drawback that the mark is subject to peeling or wear because of friction or abrasion so as to become indistinguishable in particular, since the adhesion is very small and the frequency of maintenance is high, in a case of printing to a plated product the mark becomes indistinguishable as the product is used. Also, attaching a printed seal causes the same problem as the case of printing.
According to the conventional method in which a concave portion is formed on the surface by cutting, carving, etching, molding or the like, and ink, paint or the like is poured into the concave portion, since the ink or the like is embedded into the concave portion, the adhesion and the abrasion resistance are improved. However, elaborate work is required to keep the ink or the like confined to the concave portion. Further, the processing cost becomes higher because it is necessary to increase the processing depth of the concave portion and to wipe or grind the surface after the ink or the like is poured. Also, since the size of the processing tool is limited in the case of cutting, carving or molding and a mark is formed by corrosion in the case of etching, it is difficult to form narrow and clear lines in either case.
Drawbacks of the conventional method in which a thin film is formed on the surface of a metal base by ion plating, the surface of the base is exposed by laser marking, and thereafter a gold plating layer is applied include the drawback that the variation of the color is limited. Drawbacks of the conventional method in which a masking layer is formed on the surface of a metal base, the surface of the base is exposed by laser marking, and thereafter ion plating is conducted include the drawback that the processing cost is high.
Drawbacks of the conventional method in which hammering, carving, etching or the like is conducted to a plated product also include the drawback that only a simple letter or picture an be formed and the mark is not conspicuous for its appearance.
Drawbacks of the conventional method for forming a mark by directly printing to the surface of a base or the surface of the plated base, or the conventional method in which a printed seal is attached also include the drawback that the use of these methods is limited to only a certain area where the adhesion or the abrasion resistance is not required so much. The conventional method by hammering, carving etching, molding, or the like has a limitation that it is applied only to a case of a simple letter or picture from the viewpoint of the cost.
In order to solve the above-mentioned problems, the present invention provides a method for easily forming a colored display having superior conspicuity, corrosion resistance, adhesion and abrasion resistance and a product treated according to method by conducting laser marking to the surface of a plating layer, then applying another plating layer to the surface of the plating layers to which laser marking is conducted or applying ink or paint to the surface of the plating layers to which laser marking is conducted.
According to the first aspect of the present invention, there is provided a method for forming a mark having superior conspicuity, wherein plural plating layers each having a different hue are formed on a base, the upper plating layer is removed by laser marking so as to reveal the color of the underlying plating layer, and thereby the color difference between a mark and the upper plating layer is made clear. With this methods it is possible to color a mark, and also form fine and narrow lines by laser marking, whereby conspicuity and the superiority in design of a mark to be used can be greatly improved.
According to the second aspect of the present invention, there is provided a method for forming a mark, wherein plural plating layers formed on a base are comprised of the combination of a nickel plating layer and a chromium plating layer formed thereon. The combination of the yellowish and bright color of the nickel plating layer and the bluish and bright color of the chromium plating layer makes the mark conspicuous. Also, in order to obtain corrosion resistance of the mark, the nickel plating layer has a thickness of 5 xcexcm or more, and the depth of the laser marking processing is targeted for around 2 to 3 xcexcm. The allowable error in the depth of the processing is limited to an extent within the thickness of the nickel plating layer.
According to the third aspect of the present invention, there is provided a method for forming a mark, wherein a vacuum plating layer of titanium nitride or zirconium nitride is formed on the plural plating layers by a PVD method. It is possible to obtain various colors including gold, brown, or gray as the color of the surface layer, and to obtain a mark having superior conspicuity by varying the combination of the surface color and the nickel color in tho mark.
According to the fourth aspect of the present invention, in the method for forming a mark according to the second or third aspect of the present invention, another material is used for each plating layer, and the combination of the surface layer color and the mark nickel color can freely be varied.
According to the fifth aspect of the present invention, there is provided a method for forming a mark, wherein plural plating layers are formed on a base, the is upper plating layer is removed by laser marking, and another plating layer is applied to a mark portion. The color difference between the mark and the upper plating layer enables the mark to have superior conspicuity. With this method, it is possible to color a mark and also to create fine and narrow lines by means of the laser marking, so as to greatly improve the conspicuity and the design.
According to the sixth aspect of the present invention, there is provided a method for forming a mark, wherein plural plating layers formed on a base are constructed of the combination of a nickel plating layer and a chromium plating layer formed thereon, and another plating layer is applied to a mark portion so as to make the mark conspicuous. If another plating layer is applied to the upper plating layer made of chromium, the adhesion is insufficient and the plating layer applied to the upper layer can be easily removed by wiping with a hand or polishing with airplane cloth. On the other hand, with this method, since another plating layer is applied to the nickel plating layer which forms the surface of the mark, the adhesion is sufficient and the plating cannot be removed. Also, in order to obtain corrosion resistance of the mark, the nickel plating layer has a thickness of 5 xcexcm or more, and the depth of the laser marking processing is targeted for around 2 to 3 xcexcm. The depth variance of the processing is limited to an extent within the thickness of the nickel plating layer.
According to the seventh aspect of the present invention, in the method for forming a mark according to the sixth aspect of the present invention, the kind of the plating layer applied to the mark portion is varied, and thereby the color of the mark portion can freely be varied.
According to the eighth aspect of the present invention, there is provided a method for forming a mark, wherein plating layers are formed on a base, a concave portion or concavo-convex portions is provided on the surface of the plating layers, and the concave portion or concavo-convex portions is colored with ink or paint. With this method, it is possible to display fine and narrow lines, so as to greatly improve the conspicuity and the design. Also, since the surface to which laser marking is conducted is rough, the contact area with the ink or paint is increased and an anchoring effect is obtained. As a result, the adhesion to ink or paint and the abrasion resistance is greatly improved. Also, even if the color of the mark has gone the mark formed by laser marking is still left. There is no likelihood that the mark may completely disappear.
According to the ninth aspect of the present invention, there is provided a method for forming a mark, wherein plating layers are formed on a base, a mask is formed on the surface of the plating layers, laser marking is conducted to the surface of the plating layers together with the mask, and thereby a colored mark can be obtained without bleeding of ink or paint. With this method, it is possible to save the trouble of setting the position of coloring and prevent the problem of dislocation. The mask is removed after the coloring, the adhesion of ink or paint to the mask is not a problem. It is possible to widely select a method of coloring, and thereby the workability is greatly improved and the cost is reduced.
According to the tenth aspect of the present invention, in the method for forming a mark according to the ninth aspect of the present invention, the combination of the depth of laser processing and the thickness of the mask is varied, and thereby the thickness of the coloring can be selected depending on the object or use. With this method, it is possible to improve the quality and variation of the mark.
According to the eleventh aspect of the present invention, in the method for forming a mark according to the tenth aspect of the present invention, the masking method can be changed in the case where the mask material is resin. It is possible to select applying or printing resist ink or paint. As a result, it is possible to change the thickness of the mask depending on the object or use, and thereby the variation of the mark can be increased.
According to the twelfth or thirteenth aspects of the present invention, in the method for forming a mark according to the eighth or ninth aspect of the present invention, the coloring method can be selected depending on the depth of laser processing and the thickness of the mask, and thereby the best coloring method can be selected depending on the object or use.
According to the fourteenth aspect of the present invention, there is provided a faucet product on which a colored mark having a desired text or picture is formed by the method for forming a mark according to any one of the first to thirteenth aspects of the present invention.